简介:目的:构建40S核糖体蛋白S6的原核表达载体,表达并纯化S6蛋白,将其作为底物用于S6激酶(S6K)的体外活性测定。方法:采用RT-PCR方法从人胚肾细胞HEK293中获取S6cDNA,将扩增产物克隆至大肠杆菌表达载体中,进行酶切及测序鉴定;IPTG诱导GST-S6融合蛋白在大肠杆菌中表达,用谷胱甘肽亲和层析纯化GST-S6,免疫沉淀法检测该蛋白是否可作为底物用于S6K的体外激酶活性测定。结果:酶切及测序鉴定表明构建了S6原核表达载体,并表达及纯化出GST-S6融合蛋白,相对分子质量为55×103。该蛋白可用于S6K的体外激酶活性测定,特异性强。结论:S6蛋白的克隆、表达与纯化成功,可用于S6K的体外激酶活性测定,为研究S6K的功能奠定了基础。
简介:Thereareabout17chromosomesinyeastSaccharomycescerevisiae.Amiddlesizedchromosome,chromosomeV,waschoseninthisworkforstudyingandconstructingthephysi-calmaps.ChromosomeVfromstrainA364awasisolatedbypulsed-fieldgradientgelelectrophoresis(PFGE).GelslicescontainingchromosomeVDNAweredigestedwithtworarecuttingenzymes,NotⅠandSfiⅠ,andthree6-Ntrecognizingenzymes,SmaⅠ,SstⅡandApaⅠ.Severalstrategies-partialorcompletedigestions,digestionwithdifferentsetsoftwoenzymes,andhybrid-izationwithclonedgeneticallymappedprobes(CAN1,URA3,CEN5,PRO3,CHO1,SUP19,RAD51,RAD3)——wereusedtoaligntherestrictionfragments.Thereare9,9,15,17,and20sitesforNotⅠ,SfiⅠ,SmaⅠ,SstⅡandApaⅠrespectivelyinthemapoftheA364achromosomeV.Itstotallengthwascalculatedtobe620Kb(Kilo-bases).Thedistributionsofthecuttingsitesforthesefiveenzymesthroughthewholechromosomearenotuniform.Acomp-arisonbetweenthephysicalmapandthegeneticmapwasalsomade.
简介:Monitoring.We,ecologists,hearthewordnearlyeveryday.Fromthemostunexpectedcornersthiswordspringsout,muchusedandabused.Oneonehand,itisoftenusedbymypeerstojustifytheirwork,theirprojectoreventheirexistenceasscientists.Theyclaimtodousefulwork,becausetheymonitorsomephenomenonoranother.This,goesthear-
简介:Microarrayhasbecomeapopularbiotechnologyinbiologicalandmedicalresearch.However,systematicandstochasticvariabilitiesinmicroarraydataareexpectedandunavoidable,resultingintheproblemthattherawmeasurementshaveinherent"noise"withinmicroarrayexperiments.Currently,logarithmicratiosareusuallyanalyzedbyvariousclusteringmethodsdirectly,whichmayintroducebiasinterpretationinidentifyinggroupsofgenesorsamples.Inthispaper,astatisticalmethodbasedonmixedmodelapproacheswasproposedformicroarraydataclusteranalysis.TheunderlyingrationaleofthismethodistopartitiontheobservedtotalgeneexpressionlevelintovariousvariationscausedbydifferentfactorsusinganANOVAmodel,andtopredictthedifferentialeffectsofGV(genebyvariety)interactionusingtheadjustedunbiasedprediction(AUP)method.ThepredictedGVinteractioneffectscanthenbeusedastheinputsofclusteranalysis.Weillustratedtheapplicationofourmethodwithageneexpressiondatasetandelucidatedtheutilityofourapproachusinganexternalvalidation.
简介:Threetypesofroughsurfacewereprocessedbylaserirradiationonthe3Cr2W8Vmaterialhot-workdiesteelsurface.Thewearexperimentswithsmoothsurfaceandroughsurfacesampleswererepeatedonthepin-traywearmachine.Accordingtothewearresults,westudiedtheregularityofwearresistanceofdifferentroughsurfacesamples.Theresultsindicatedthatbionicroughsurfacecanimprovethewearresistanceofthematerialandthewearresistancecanbeincreased1-2times,comparedwiththesmoothsurface.Also,thewearresistanceoftheroughsurfacewasaffectedbylasercurrentanddurationofimpulse.Thebiggerthelasercurrentortheimpulseduration,thebetteristhewearresistance.Whenthedistancebetweenthesamekindofunitswhicharedistributedonthesurfacesischanged,thewearresistancechanges.Thewearresistanceofabionicroughsurfaceonwhichthegridunitsweredistributedatspacingof1mmwasthebest.Andwedesignedthewearmodels.
简介:目的:构建EF-1α-Flag到pcDNA3.0表达载体上,在哺乳动物细胞中表达并纯化延伸因子1α(EF-1α),测定其对体外蛋白翻译的影响。方法:通过PCR技术从293T细胞cDNA文库中扩增EF-1α基因片段,连接到pcDNA3.0载体上,经电泳、测序和转入细胞中检测EF-1α-Flag蛋白表达等方式验证所构建的重组质粒是否正确,然后经Flag肽置换法纯化出EF-1α蛋白用于体外蛋白翻译实验,萤光素酶活性检测翻译出的蛋白含量。结果:测序和蛋白表达鉴定结果表明扩增的EF-1α-Flag基因序列正确,所构建的重组载体在哺乳动物细胞中能获得表达;考马斯亮蓝染色发现经Flag肽置换的EF-1α蛋白纯度较高,在体外蛋白翻译实验中EF-1α蛋白能促进蛋白的翻译。结论:从哺乳动物细胞中纯化的EF-1α蛋白能促进蛋白翻译,可能与其作为翻译延伸因子相关,为进一步研究EF-1α的功能奠定了基础。
简介:心肌肌钙蛋白I(CardiacTroponinI,cTnI)作为诊断心肌损伤的血清标志物之一,同其它检测指标相比,具有出现时间早、诊断窗口期宽、特异性强、诊断阈值明确及检测快速等优点。由于心肌肌钙蛋白I为心肌细胞所特有,因此在心肌缺血性损伤、心肌非缺血性损害的诊断及骨骼肌损伤的鉴别诊断中得到了广泛应用。目前正逐渐取代包括CK-MB在内的其它血清酶检测指标而成为判断心肌损伤,特别是诊断急性心肌梗死(AcuteMyocardialInfarction.AMI)的“金标准”。同时心肌肌钙蛋白I对心肌疾病的病情监测、疗效观察及预后评估都具有较高的临床应用价值。本文对cTnI的国内外临床应用研究进展进行综述。